MC68HC705P6A Datasheet, PDF (77/130 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Advance Information — MC68HC705P6A
Section 9. Analog Subsystem
9.1 Contents
9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
9.3 Analog Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
9.3.1 Ratiometric Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
9.3.2
9.3.3
Reference Voltage (V_REFH) . . . . . . . . . . . . . . . . . . . . . . . . . 78
Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
9.4 Conversion Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
9.5 Digital Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
9.5.1 Conversion Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
9.5.2 Internal versus External Oscillator . . . . . . . . . . . . . . . . . . . . 79
9.5.3 Multi-Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
9.6 A/D Status and Control Register (ADSC) . . . . . . . . . . . . . . . . . 80
9.7 A/D Conversion Data Register (ADC). . . . . . . . . . . . . . . . . . . .82
9.8 A/D Subsystem Operation during Halt/Wait Modes . . . . . . . . . 82
9.9 A/D Subsystem Operation during Stop Mode. . . . . . . . . . . . . . 82
9.2 Introduction
The MC68HC705P6A includes a 4-channel, multiplexed input, 8-bit,
successive approximation analog-to-digital (A/D) converter. The A/D
subsystem shares its inputs with port C pins PC3–PC7.
MC68HC705P6A — Rev. 2.0
MOTOROLA
Analog Subsystem
Advance Information
77